Propionic acid oil, also known as primary oleic acid, is a short chain saturated fatty acid, chemical formula CH3CH2COOH, molecular weight 74.08. Propionic acid belongs to weak electrolyte (Ka=1.34 × 10-5), its aqueous solution is weakly acidic, but highly corrosive, and the steam is irritating to the skin and respiratory tract. Under normal temperature and pressure, propionic acid is a colorless, clear, oily liquid with an unpleasant rancidity and pungent smell. It is miscible with water, ethanol, chloroform and ether.

Propionic acid is mainly used as food preservative and mildew inhibitor, as well as as inhibitor of medium viscosity substances such as beer, nitrocellulose solvent and plasticizer, and it can also be used in the preparation of nickel plating solution, food flavor, medicine, pesticide, mildew inhibitor, etc.

Product Information :

Usage :

Uses of propionic acid oil:

1. Used as organic reagent, esterification agent and plasticizer. Because propionic acid can dissolve most organic substances, propionic acid is also a commonly used organic solvent.
2. Propionic acid can be used in some pickling and polishing solutions, as a buffer in weak acid solutions (such as zinc plating and chemical nickel plating), as an additive in semi bright nickel plating electrolyte, and in zinc and cadmium passivation solutions to improve the adhesion of the passivation film, and is often used to adjust the pH of weak acid plating solutions.
3. Synthesis of derivatives of propionic acid. Propionic acid can be used to produce propionate. In addition, sodium propionate, calcium propionate and propionic acid can also be used as food preservatives, and can also provide calcium, sodium, potassium and other trace elements for food or feed.
4. Determination of aromatic diamines, gas chromatography analysis standard, can also be used to inhibit the growth of mold in insect cell culture.
5. As a food preservative, propionic acid can prevent food from rotting and deteriorating due to microbial action, and extend the storage time, especially for the preservation and storage of bread and pastries. Propionic acid can also be used to preserve poultry feed
6. As an intermediate of spices, propionic acid is used with acetic acid in butter, milk, and yogurt. It can be used as a raw material of synthetic spices to give spices a natural sour taste.
7. It can be used as pharmaceutical intermediates, such as propionic anhydride as propionylation agent for medicine, and as antibiotic drugs, such as keratosamycin propionate. It can also be made into a dispersant containing 15% calcium propionate and an ointment or solution containing 12.3% sodium propionate, which can treat diseases caused by skin parasitic mold, and can also be used as an intermediate of medicine.
8. Propionic acid can also be used to synthesize its esters and derived intermediates. Propionic acid esters can be widely used as herbicides, resin modifiers, disinfectants, plasticizers of cigarette filter tips, etc.
9. Propionate esters formed from lower alcohols are excellent solvents, which are widely used in paint industry and can also be used to synthesize cellulose propionate. Cellulose acetate propionate produced from propionic acid can be used in automobile parts, TV sets, etc.

Manufacturing :

Preparation of propionic acid oil:

Microorganisms such as propionic acid can use a variety of fermentable sugars to produce propionic acid. In industry, a variety of biomass can be first hydrolyzed into monosaccharides such as glucose or xylose with acid or enzyme, and then introduced into a reactor for fermentation. After fermentation, add lime milk, precipitate, filter, add sodium sulfate for double decomposition reaction, filter and concentrate, add sulfuric acid for conversion, and then fractionate. The fermentation reactor can adopt the immobilized protoplast tower reactor, and the cells can be fixed in the following form: the surface of the pre sterilized packing ring is covered with a layer of sterilized solution containing 20% gelatin and 1.5% shellac by immersion method, and after drying, 2.5% glutaraldehyde aqueous solution is sprayed, so that the polymer on the surface of the packing ring is cross-linked to increase the strength. Rinse with sterile water, then sterilize with ethylene glycol, discharge ethylene glycol and blow it clean with sterile nitrogen. Thereafter, propionic acid bacteria culture liquid is added to the reactor filled with the filling ring to form a fixed cell membrane on the surface of the filling ring, and then continuous feeding can be carried out for fermentation.

Refining method:

Dry and distill with anhydrous sodium sulfate to collect 139~141 ℃ fraction. Distillate with a small amount of solid potassium permanganate and then distill. It can also be converted to ethyl ester for fractionation. The ethyl propionate was refined by hydrolysis.

1. The direct oxidation of low carbon hydrocarbons can produce formic acid and propionic acid when using low carbon hydrocarbons as raw materials to produce acetic acid, and propionic acid can be obtained after separation.

2. Propanoic acid was synthesized by one step reaction of ethylene with carbon monoxide and water under the catalysis of nickel carbonyl. The reaction conditions are 250 ～ 320 ℃ and 10 ～ 30MPa.

3. Oxidation of propionaldehyde In the presence of manganese propionate catalyst, propionaldehyde reacts with air or oxygen to generate propionic acid.

4. Propionitrile hydrolysis method is prepared by hydrolysis of propionitrile under the catalysis of concentrated sulfuric acid.

5. Acrylic acid method is prepared by hydrogenation and reduction of acrylic acid.

6. Ethanol carbonylation method Ethanol is prepared by reacting with carbon monoxide in the presence of catalyst.

Chemical properties of propionic acid oil:

React with inorganic substances

The hydrogen atom on the carboxyl group of propionic acid can be partially ionized into hydrogen ions (protons) in the aqueous solution and released, thus causing propionic acid to be acidic. Propionic acid is a weak monobasic acid in aqueous solution, pKa=4.87 (25 ℃).

1. Because propionic acid is an acid, propionic acid can neutralize with alkali to generate corresponding propionate:

Reaction of propionic acid and sodium hydroxide: CH₃CH₂COOH+NaOH=CH₃CH₂COONa+H₂O

Reaction of propionic acid and calcium hydroxide: 2CH₃CH₂COOH+Ca (OH)₂=(CH₃CH₂COO) ₂Ca+2H₂O

Reaction of propionic acid and ammonia: CH₃CH₂COOH+NH₃ · H₂O=CH₃CH₂COONH₄+H₂O

2. Propionic acid can undergo double decomposition reaction with weak acid salts such as carbonate:

Reaction of propionic acid and carbonate: 2CH₃CH₂COOH+CO₃^2-=2CH₃CH₂COO ^–+H₂O+CO₂ ↑

3. Due to the weak acid nature of propionic acid, propionic acid is corrosive to many metals, such as iron, magnesium and propionic acid react to generate hydrogen and metal propionate.

Reaction of propionic acid with iron: Fe+2CH₃CH₂COOH=(CH₃CH₂COO) ₂Fe+H₂ ↑

Reaction of propionic acid and aluminum: 2Al+6CH₃CH₂COOH=2 (CH₃CH₂COO) ₃Al+3H₂ ↑

Reaction of propionic acid with magnesium: Mg+2CH₃CH₂COOH=(CH₃CH₂COO) ₂Mg+H₂ ↑

Substitution reaction of hydroxyl group on carboxyl group

The – OH in propionic acid can be used as a group and replaced by carboxyl, halogen or alkoxy to generate acid anhydride, acyl halide or ester and other propionic acid derivatives, respectively.